Led by a police escort, the couple of hundred demonstrators carried banners calling the United States the "guardian and master of [the] ruling Mafia in Afghanistan" as well as images of burned and bandaged children.

The protesters said they were angry not only about the civilian toll from ongoing NATO military operations in Helmand province but also a traffic accident Friday involving an SUV driven by DynCorp International contractors that killed four Afghans.

"Many times NATO troops and these cars have killed our innocent people. They never care whether we are Afghans or animals," said Samia, 26, an activist from Kabul who took part in the demonstration.

Samia, who like many Afghans goes by only one name, said that she did not want the Taliban to return to power in Afghanistan but that NATO has only aggravated the situation over the past decade and fed a parasitic and dependent Afghan government.

"We want NATO troops and American troops to leave Afghanistan. Even with their huge army, they couldn't do anything in the past 10 years. And in the future, they won't be able to do anything. The result will be just death and casualties, and our innocent Afghan women and children will die," she said.

After the traffic accident on Friday near the U.S. Embassy, an angry crowd surrounded the DynCorp vehicle and set it on fire. DynCorp employees who arrived to help were attacked, and their vehicle also was torched.

"We poor people are not just here to be killed," said an elderly woman named Rabia who was in Sunday's protest. She said she had witnessed the reaction to the traffic accident Friday. "The people were so emotional. They were throwing stones at the Americans' vehicles. If the police hadn't taken the Americans away, the people would have torn them to pieces. If I had the chance to do that, I would do the same thing."

Also Sunday, Afghan officials said six people were killed when a minibus hit a roadside bomb in Kandahar province.

NATO said insurgents have killed more than 590 Afghan civilians and wounded 1,350 this year.